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hejunqi

捐助贵宾 (正式写手)

应助: 0 (幼儿园)
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帖子: 432
在线: 128.8小时
虫号: 978893
注册: 2010-03-22
性别: GG
专业: 化工系统工程

[求助] 【求助】乙醇与水的分离设计的Aspen工艺模拟出现问题！

乙醇与水分离的过程：
现有乙醇—水原料24.468kmol/h,其中水含量为14%，利用图1.1所示工艺制取无水乙醇，要求产品中乙醇摩尔分数不低于0.99.已知恒沸精馏塔理论板数为20，在第6块板处进料，塔顶采出流量为28.60kmol/h，回流量82.51kmol/h;回收塔理论板数为15，从塔顶进料，塔釜热负荷为80kw，要求塔釜进料中的苯摩尔分数小于0.01。用ＡＳＰＥＮＰＬＵＳ软件对该流程进行模拟，并确定夹带剂苯的适宜用量？

谢谢各位帮忙，如果解决金币可以追加，因为每次初始悬赏的金币都没花完，所以这次少设了点！还请各位费心帮忙。。

设计的工艺流程模拟出现的问题如下：
  * WARNING IN THE "STREAM" PARAGRAPH WHICH BEGINS ON LINE 62
   STREAM NAME: FEED
   COMPONENT MOLE FLOWS OF SUBSTREAM: "MIXED"
   ARE NORMALIZED TO THE TOTAL MOLE FLOW VALUE.

  Flowsheet Analysis :

Block $OLVER01 (Method: SECANT  ) has been defined to converge
      specs : DS-1

COMPUTATION ORDER FOR THE FLOWSHEET:
$OLVER01 DST1 DST2
(RETURN $OLVER01)

->Calculations begin ...

Block: DST1    Model: RADFRAC
  *** SEVERE ERROR
   SUM OF PRODUCT FLOW SPECIFICATIONS EXCEEDS FEED FLOW;
   PLEASE CHECK "COL-SPECS" AND "PRODUCTS" SPECIFICATIONS.

  * WARNING
   REST OF BLOCK BYPASSED DUE TO SEVERE ERROR.

Block: DST2    Model: RADFRAC

   Convergence iterations:
      OL ML IL    Err/Tol
      1 1 10 1366.4
      2 1 10 750.12
      3 1 10 466.95
  **  ERROR
   THE FOLLOWING STAGES DRIED UP (VAPOR AND/OR LIQUID FLOW APPROACHES 0):
      15

  **  ERROR
   BLOCK DST2 IS NOT IN MASS BALANCE:
   MASS INLET FLOW = 0.22590312E-02, MASS OUTLET FLOW = 0.11824837E+00
   RELATIVE DIFFERENCE = 0.51344726E+02

> Beginning Convergence Loop $OLVER01 Method: SECANT
1 vars not converged, Max Err/Tol  -0.10000E+03

Block: DST1    Model: RADFRAC
  *** SEVERE ERROR
   SUM OF PRODUCT FLOW SPECIFICATIONS EXCEEDS FEED FLOW;
   PLEASE CHECK "COL-SPECS" AND "PRODUCTS" SPECIFICATIONS.

  * WARNING
   REST OF BLOCK BYPASSED DUE TO SEVERE ERROR.

Block: DST2    Model: RADFRAC

   Convergence iterations:
      OL ML IL    Err/Tol
      1 1 10 306.04
      2 1 10 249.74
      3 1 10 201.24
  **  ERROR
   THE FOLLOWING STAGES DRIED UP (VAPOR AND/OR LIQUID FLOW APPROACHES 0):
      12  13  14  15

  **  ERROR
   BLOCK DST2 IS NOT IN MASS BALANCE:
   MASS INLET FLOW = 0.23513696E-02, MASS OUTLET FLOW = 0.10290536E+00
   RELATIVE DIFFERENCE = 0.42764007E+02

> Loop $OLVER01 Method: SECANT    Iteration 2
  * WARNING
   SPEC FUNCTION NOT CHANGING, POSSIBLY HAS A FLAT  RESPONSE
   TO THE MANIPULATED PARAMETER WITHIN THE GIVEN BOUNDS.

1 vars not converged, Max Err/Tol  -0.10000E+03
  **  ERROR
   Convergence block $OLVER01 did not converge
   normally in the final pass

->Simulation calculations completed ...

  ***  Warning(s) were issued during Input Translation ***
  ***  Check the Run Status Results for more Information ***

            ***  Summary of Simulation Errors  ***

               Physical
               Property       System       Simulation
  Terminal Errors    0             0             0
Severe Errors    0             0             2
         Errors    0             0             5
      Warnings    0             0             3

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